Boring-bit.



PATENTBD MAY 7, 1901 N. STAUB. BORING BIT.

PPLIGATION FILED JULYBl, 1905.

UNiiThZD snirnnr cri ics NICOLAUS STAUB, OF SCHIFFWEILER, GERMANY.

Specification of Letters Iiet-ent.

Patented ma '2, 1907.

Application filed July 31,1905. Serial to. 272.131.

To all who) it "may concern.-

Be it known that I, NICULAUS STAUB, a subject of the Emperor of German residing at Ottwcilerstrasse, Schii'i'weiier ries' ()ttweiler, in the Empire of Germany, locksmith, have invented certain new and useful improvements in Boring-Bits. of which the following is a specification.

This invention has for its object a composite rose hit, in which a number of radiaily l lormedwedge-shaped cutters are arranged alternately and are held in position by means oi a centralcutter.

'lhe borinc bit which forms the subject of the present invention dill'crs from those hitherto cmployed owing to the l'ac't that with the central cut ter, the cutter bar is employed in holding the outer cutters in place in the 3 By this means the advantage is ob- I socket. I ta ned that the cutters maybe released without the employment of a special tool merely by striking the cutter hat or the bottom of the socket.

The invention is illustrated in the aceomshaped outer cutters I), provided with wedgeshaped their sides which are directed one to t other; they also have curved surfaces 5 m of I dili'erent curvature. lhesc surfaces l present the same radius of curvature as the adjoining faces of the circular cutter a which is formed with a llat cutting edge i.

'lhe Wedge-shaped cutters are held in the bore 1/, which widens at a and j, of a socket c, on. the one hand in the known manner by means of the circular cutter a resenting the form of a truncated cone, an on the other cutting edges 11' and stopped at n on hand by the cutter bar 71, which passes through the opening 9 in the socket and is likewise in the form of a truncated cone.

F or the purpose of assembling the tool, the cutters are arranged in position for use, their cutting edges resting upon a plane surface. The socket is then passed from above over tangs of the cutters and tapped with a Wooden mallet. The tool may be conveniently "taken apart by holding it firmly and then striking" the cutter bar It. -Uponthe withdrawal of this latter the cutters may be loosened and readily removed.

iiavin now particularly described and ascertained the nature of in; said invention formed, it (lttllLtC that what- I claim is l member having an opening in its bottom, raf dial cutters seated in the socket of said meniher, a cent rai cutter enga 'mg the upper part of said radial cutters, and a cutter bar passber and engaging the lower part of the radial cutters.

2. A composite rose bit comprisinga socket member having an opening in its bottom, radial cutters seated in the socket of said nemher, a central cutter having a shank located between and engaging said radial cutters, and a cutter bar passing through the opening in the socket member and locatcd'between and engaging the radial cutters.

3. A composite rose bit comprising a socket i member having an opening in'its b0ttom,ra

. dial cutters each having curved inner surfaces at their top and bottom and seated in said socket member, a conical central cutter inserted between the radial cutters and en-,

aging their curved top surfaces, and a conand in what manner the same is to be per ing through the opening in the socket metn- 1. A composite rose bit comprising a socket real cutter bar passing through the opening in the socket member and located between the radial cutters and engaging their curved bottom surfaces. I

my hand in presence of two subscribing witnesses this 25th day of October 1906.

STAUB.

, N ICOLAUS Witnesses: h'iAGDALENA STAUB,

l j in testimony whereof Ihave hereunto set i "XVALTER HOUSING. 

